Peter Franklin is a Conservative policy advisor, speechwriter and contributor to The Guardian’s Comment Is Free.

Warning: If you don’t care about greenhouse gas emission or don’t believe in global warming then this article is not for you. In fact, it will make no sense at all. If, however, you are of the opinion that it might not be the best idea to let carbon dioxide levels double and triple just to see what happens, then read on.

David Cameron is someone who believes that we need to take action to reduce our carbon emissions. However, according to his interview with GQ magazine he seems to be against a tax on aviation fuel: “I don’t want to make air travel the preserve of the rich.”

This is something that was welcomed by our esteemed Editor and other visitors to Conservative Home. We wouldn’t want to “price people out of the skies”, they say. There would appear to be some misunderstanding here. The mainstream environmental movement doesn’t want people to fly less, rather it doesn’t want them to fly more. There is a very good reason for this.

Aircraft are championship carbon emitters – not just as a result of the huge quantities of fuel they burn, but because of the altitude at which they release their greenhouse gases. Each tonne of carbon dioxide released in the air has two to three times the global warming effect of a tonne released nearer to ground level.

Moreover, the rate of growth in air travel means that aircraft emissions are outstripping those of any other major sector. Climate change experts have done the sums, projecting forward the various growth rates to see where we’re likely to stand in 2050. At a time when Britain’s emissions will need to be 60% down on 1990 levels (a target adopted by all the main parties and endorsed by the weight of opinion amongst scientists), aircraft emissions look set to gobble up most or all of Britain’s carbon budget. In other words, emissions from every other sector would have to be zero or close to it.

Ah, but isn’t there a danger in extrapolating trends so far into the future? Can we really expect air travel to continue growing at the current rate for the next forty years? Well, yes, we can. Even in developed countries like Britain, the market for air travel is as far from being saturated today as the market for road travel was forty years ago. Moreover, air space is very much less constrained than road space. In the absence of government action, all that can stop the growth of the air travel market is economic stagnation, a catastrophic rise in the oil price or a halt to the development of new airports.

But won’t technology come to the rescue? Energy efficiency and low carbon energy sources are making a big impact everywhere else, so why not aviation? Unfortunately, aircraft are uniquely resistant to technological improvement. There is no viable alternative to currently used aviation fuels. Various operational, engine and fuel efficiencies are making some impact on emissions per passenger mile, but the rate of improvement is much slower than the rate of market growth – and has already been taken into account in the calculations I mentioned earlier. Even if there were to be some stunning technological breakthrough – say fuel cell powered jet engines – it will take many decades before current aircraft designs touchdown for the last time.

The hard truth is that the only way to stabilise aviation emissions is to stop the growth in demand. And that will require some form of market intervention to steady the cost of air travel relative to living standards. This implies some kind of tax or levy, (the proceeds of which could be used to help the developing world acquire alternative communication networks).

Yes, I realise that all of this will require international agreement, which won’t be easy to say the least. However, the same will be true of any meaningful action on climate change – without which we might as well all go home and prepare for the worst.

That in a nut shell is the substantive case, but what of the political case? Can we really afford to tell the voters that we want to price them out of the skies? As I’ve explained it’s not about reducing access to air travel, but restricting the level of growth to the rate of fuel efficiency improvement. That oughtn’t to be too hard a message to sell. But there’s a more serious point about the purpose of the Conservative Party.

Is our raison d’etre to facilitate the growth of material consumption regardless of the consequences? As conservatives we should be philosophically equipped to grasp that there’s more to life than bread alone. And on a more practical level, we should realise that while technological and economic progress may be unlimited, our existence on this Earth is bound by other constraints. For instance, the greater prosperity of the last few decades has enabled us to pay the financial costs of family breakdown, but the personal pain and social disintegration that comes with it cannot be healed with money. Our humanity, like the natural world that surrounds us, is fragile. We need to take care of both.